2024
Flat Panel TOF-PET Detectors: a Simulation Study
Orehar M, Dolenec R, Fakhri G, Gascón D, Gola A, Korpar S, Križan P, Razdevšek G, Marin T, Chemli Y, Žontar D, Pestotnik R. Flat Panel TOF-PET Detectors: a Simulation Study. 2024, 00: 1-2. DOI: 10.1109/nss/mic/rtsd57108.2024.10658250.Peer-Reviewed Original ResearchTime resolutionAngular coverageFlat-panel detectorScintillation materialsGATE softwareAxial coverageBiograph VisionPanel detectorTotal-body coverageClinical scannerImage reconstructionDetectorReconstructed imagesHomogeneous contrastCylindrical scannerImage qualityState-of-the-artScintillationHigh-performance computingScannerPhantomResolutionCore hoursPositron emission tomographyGate
2022
Simulation study of a 50 ps panel TOF PET imager
Pestotnik R, Razdevšek G, Dolenec R, Fakhri G, Križan P, Majewski S, Studen A, Korpar S. Simulation study of a 50 ps panel TOF PET imager. Journal Of Instrumentation 2022, 17: c12010. DOI: 10.1088/1748-0221/17/12/c12010.Peer-Reviewed Original ResearchPET scannerGamma detectorGamma raysTime-of-flight positron emission tomographyState-of-the-art clinical PET scannersGamma detection efficiencyClinical PET scannerImaging large objectsImproved time resolutionArtifact-free imagesDifferent phantomsDetector arrangementTime-of-flightBiograph VisionImage quality parametersDetection efficiencyTiming accuracyTime resolutionDetectorFWHMPositron emission tomographyReconstructed imagesRaysPositron emission tomography imagingMultichannel systemOptimization of Design Parameters of Flat Panel Limited Angle TOF-PET Scanner: a Simulation Study
Orehar M, Dolenec R, Fakhri G, Gascón D, Gola A, Korpar S, Križan P, Razdevšek G, Pestotnik R. Optimization of Design Parameters of Flat Panel Limited Angle TOF-PET Scanner: a Simulation Study. 2022, 00: 1-4. DOI: 10.1109/nss/mic44845.2022.10399330.Peer-Reviewed Original ResearchImage quality phantomFlat-panel detectorGATE softwareRing scannerPanel detectorDetection chainState-of-the-artNEMA standardsOpen geometryImage reconstructionReconstructed imagesPositron emission tomographyState-of-the-art scannersScannerPhantomDetectorPhotodetectorsElectronNEMAMaterial costGatePositron
2019
Limited-Angle TOF-PET for Intraoperative Surgical Application
Sajedi S, Bläckberg L, Vittum B, Devabhaktuni A, Nejad M, Fakhri G, Choi H, Sabet H. Limited-Angle TOF-PET for Intraoperative Surgical Application. 2019, 00: 1-4. DOI: 10.1109/nss/mic42101.2019.9059690.Peer-Reviewed Original ResearchSentinel lymph nodeHigh-resolution positron emission tomographyTOF-PETNear-infraredDetector ringDetector blockIncreasing acquisition timeTorso phantomHot spheresBottom detectorPositron emission tomographyTime resolutionDetectorIdentification of sentinel lymph nodesAcquisition timeSentinel lymph node identificationReconstructed imagesAccurate identification of sentinel lymph nodesActivity concentrationsWhole-body positron emission tomographyComplete tumor removalFalse negative rateImage slicesImprove patient recoveryPatient bed
2018
End-to-End Lung Nodule Detection in Computed Tomography
Wu D, Kim K, Dong B, Fakhri G, Li Q. End-to-End Lung Nodule Detection in Computed Tomography. Lecture Notes In Computer Science 2018, 11046: 37-45. DOI: 10.1007/978-3-030-00919-9_5.Peer-Reviewed Original ResearchDeep reconstruction networkLung nodule detectionReconstruction networkEnd-to-end detectorMedical imagesLung Image Database Consortium image collectionNodule detectionEfficient network trainingReconstructed imagesConvolutional neural networkEnd-to-endSuperior detection performanceRaw dataComputer visionCAD systemCNN detectorNetwork trainingImage collectionNeural networkDetection performanceImage spaceDetection taskDetection systemModern medical imagingFanbeam projectionsA novel depth-of-interaction rebinning strategy for ultrahigh resolution PET
Kim K, Dutta J, Groll A, Fakhri G, Meng L, Li Q. A novel depth-of-interaction rebinning strategy for ultrahigh resolution PET. Physics In Medicine And Biology 2018, 63: 165011. PMID: 30040073, PMCID: PMC6375090, DOI: 10.1088/1361-6560/aad58c.Peer-Reviewed Original ResearchConceptsDepth of interactionReconstructed imagesAlternating direction methodReconstructed image qualityPoisson log-likelihoodImage qualitySub-sampling methodPositron emission tomography systemReduce noise effectsDOI layersReconstruction frameworkDetector pixel sizePoint source experimentsQuadratic surrogatesCdZnTe detectorsAnimal positron emission tomographyLog-likelihoodDirection methodSmall animal positron emission tomographySource ExperimentPhoton countingRebinning methodSystem matrixNoise effectsSinogram
2017
Iterative Low-Dose CT Reconstruction With Priors Trained by Artificial Neural Network
Wu D, Kim K, Fakhri G, Li Q. Iterative Low-Dose CT Reconstruction With Priors Trained by Artificial Neural Network. IEEE Transactions On Medical Imaging 2017, 36: 2479-2486. PMID: 28922116, PMCID: PMC5897914, DOI: 10.1109/tmi.2017.2753138.Peer-Reviewed Original ResearchConceptsArtificial neural networkIterative reconstruction algorithmNeural networkLow-dose CT reconstructionReconstruction algorithmUnsupervised feature learningReconstructed imagesFeatures of imagesImprove reconstruction qualityNormal-dose imagesDecreasing radiation riskDevelopment of artificial neural networksFeature learningComplex featuresAuto-encoderReconstruction qualityData fidelityMachine learningSuppress noiseSmoothness constraintPhoton fluxPreservation abilityGrand ChallengeNoise reductionPriors
2014
Tof-Pet Ordered Subset Reconstruction Using Non-Uniform Separable Quadratic Surrogates Algorithm
Kim K, Ye J, Cheng L, Ying K, Fakhri G, Li Q. Tof-Pet Ordered Subset Reconstruction Using Non-Uniform Separable Quadratic Surrogates Algorithm. 2014, 963-966. DOI: 10.1109/isbi.2014.6868032.Peer-Reviewed Original ResearchSignal-to-noise ratioQuadratic surrogatesTOF-basedAlgorithm timeNoise ratioReconstruction algorithmReconstructed imagesAlgorithmConvergence rateImage qualityPET reconstructionTransmission reconstructionComputer simulationsTOF PET reconstructionTOF-PETEmission reconstructionAccurate imagingImagesSmall regionConvergenceComputerReconstructionNon-uniformityOSEM
2013
Spatially varying regularization for motion compensated PET reconstruction
Dutta J, Fakhri G, Lin Y, Huang C, Petibon Y, Reese T, Leahy R, Li Q. Spatially varying regularization for motion compensated PET reconstruction. 2011 IEEE Nuclear Science Symposium Conference Record 2013, 2156-2160. DOI: 10.1109/nssmic.2012.6551493.Peer-Reviewed Original ResearchSimulated lung lesionsRegularization schemeSpatially varying regularizationUngated reconstructionTorso phantomImage reconstruction problemContrast recoverySacrificing signal-to-noise ratioPET reconstructionSignal-to-noise ratioAnalytical approximationReconstruction frameworkQuadratic penaltyDiagonal elementsReconstruction problemLocal impulse responseCardiac motionRegularization approachReconstructed imagesFisher information matrixAutomated fashionPET imagingImpulse responseDegree of smoothnessInformation matrix
2007
Fast Monte Carlo based joint iterative reconstruction for simultaneous SPECT imaging
Ouyang J, Fakhri G, Moore S. Fast Monte Carlo based joint iterative reconstruction for simultaneous SPECT imaging. Medical Physics 2007, 34: 3263-3272. PMID: 17879789, DOI: 10.1118/1.2756601.Peer-Reviewed Original ResearchConceptsMC-JOSEMEnergy windowFast Monte CarloSignal-to-noise ratioScatter correction methodOrdered-subsets expectation-maximizationMonte CarloOrdered-subsets expectation-maximization algorithmIterative reconstruction algorithmPrimary photonsReconstruction algorithmPhoton transportSeptal penetrationDetector responseMC simulationsIterative reconstructionAttenuation distributionStandard OSEMPhotonsProjection dataPatient-specific activityDetectorReconstructed imagesScatteringEstimation of scattering
2006
Fast Monte Carlo Simulation Based Joint Iterative Reconstruction for Simultaneous 99mTc/123I Brain SPECT Imaging
Ouyang J, Fakhri G, Moore S, Kijewski M. Fast Monte Carlo Simulation Based Joint Iterative Reconstruction for Simultaneous 99mTc/123I Brain SPECT Imaging. 2006, 4: 2251-2256. DOI: 10.1109/nssmic.2006.354362.Peer-Reviewed Original ResearchMC-JOSEMAW-OSEMMonte CarloFast Monte CarloIterative reconstructionOrdered-subset expectation maximizationStandard ordered subsetsIterative reconstruction algorithmScattered photonsPhoton transportSeptal penetrationAttenuation distributionPhysical effectsIdentical physiological conditionsPatient-specific activityReconstructed imagesReconstruction algorithmActivity estimationComptonRoot mean square errorPhotonsCorrection methodCollimatorBrain perfusionDetectorMonte Carlo Modeling of Cascade Gamma Rays in PET
Zhu X, Fakhri G. Monte Carlo Modeling of Cascade Gamma Rays in PET. 2011 IEEE Nuclear Science Symposium Conference Record 2006, 6: 3522-3525. DOI: 10.1109/nssmic.2006.353759.Peer-Reviewed Original ResearchCascade gamma raysGamma raysGamma-ray emitting isotopesDetector dead timeMonte Carlo modelPET imagingGamma eventsScatter fractionQuantitative PET imagingTorso phantomSingles ratesMonte Carlo simulationsDecrease of intensityHigh-activity regionsPhantom experimentsReconstructed volumePhantomRaysCarlo simulationsDead timeDetectorReconstructed imagesCascade typeImage intensityMonte
2000
Should scatter be corrected in both transmission and emission data for accurate quantitation in cardiac SPET?
El Fakhri G, Buvat I, Almeida P, Bendriem B, Todd-Pokropek A, Benali H. Should scatter be corrected in both transmission and emission data for accurate quantitation in cardiac SPET? European Journal Of Nuclear Medicine And Molecular Imaging 2000, 27: 1356-1364. PMID: 11007518, DOI: 10.1007/s002590000304.Peer-Reviewed Original ResearchConceptsTransmission dataSingle-photon emission tomographyActivity distributionSignal-to-noise ratioCardiac single-photon emission tomographyAttenuation-corrected imagesAmount of scatterNarrow transmission windowHot compartmentActivity quantitationTransmission scanEmission dataEmission acquisitionTransmission windowReduced signal-to-noise ratioTransmission scatteringScatteringScattering componentPhantomQuantitative accuracyReduced scatteringAttenuating mediaReconstructed imagesLine sourceEmission